Anticoagulation after Hemorrhagic Transformation in Acute Cardioembolic Ischemic Stroke.

To assess the association of anticoagulation in patients with cardioembolic acute ischemic stroke (CES) who develop hemorrhagic transformation (HT) and its impact on neuroimaging and functional outcomes. This retrospective study enrolled patients presenting with CES within 48 h at a tertiary stroke center between January 2011 and August 2023. Patients who developed HT during hospitalization and underwent follow-up imaging within 1 week were included, focusing on those with hemorrhagic infarction or parenchymal hematoma type 1. Primary outcomes were HT exacerbation on follow-up imaging and 3-month modified Rankin Scale (mRS) distribution shift, comparing anticoagulation therapy (AC), antiplatelet therapy (APT), and drug discontinuation (DDDD). The safety outcome was the occurrence of symptomatic intracerebral hemorrhage (sICH), which was defined as a hemorrhage concomitant with neurological deterioration. Among 763 patients with HT (age 74.6 ± 8.9 years, 48.1% male), AC was associated with a higher incidence of HT exacerbation compared to APT (adjusted OR 0.48, 95% CI 0.29-0.80, p-value = 0.005). AC associated with a better 3-month mRS compared to both APT (adjusted OR 0.63, 95% CI 0.43-0.92, p-value = 0.017) and DD (adjusted OR 0.38, 95% CI 0.26-0.55, p-value < 0.001). sICH occurred in 5%, with rates of 1.5%, 2.1%, and 11.7% in the AC, APT, and DD groups, respectively (adjusted OR for DD vs. AC: 3.93, 95% CI 1.18-13.16, p-value = 0.026). Anticoagulation in CES patients with HT was associated with a better functional outcome and radiological exacerbation, without a significant increase in sICH risk. These findings suggest that the presence of HT should not necessarily preclude the use of anticoagulation therapy in this patient population. However, our study should be interpreted as hypothesis-generating, and confirmation from future prospective studies is warranted.